1. Field of the Invention
The present invention relates to a machine tool including an affected layer detection sensor.
2. Description of the Related Art
Examples of a machine tool including an affected layer detection sensor according to the related art are described in Japanese Patent Application Publication No. 2011-245592 (JP 2011-245592 A), Japanese Patent Application Publication No. 2010-184343 (JP 2010-184343 A), Japanese Patent Application Publication No. 2011-13147 (JP 2011-13147 A), and Japanese Patent Application Publication No. 2011-252877 (JP 2011-252877 A). In JP 2011-245592 A, a wheel spindle stock is provided with an affected layer detection sensor. The affected layer detection sensor described in such documents is brought into contact with an workpiece to detect an affected layer.
Since the affected layer detection sensor contacts the workpiece, the distal end of the sensor may be worn. In contrast, performing a precise detection using a non-contact affected layer detection sensor requires reducing a gap between the sensor and the workpiece and keeping the gap constant.